Phoenix Slides
Originally downloaded April 21, 2007. Here's another freeware option for navigating/previewing your image collection. It provides full-screen slideshow options as well, as well as recursive search. An intriguing addition over some similar tools is the ability to move files to the trash, and general support for drag/drop. The developer suggests a donation of $10-$20, but also provides the full source code. Quite generous! Apparently earlier versions sported a homemade icon the author did, but now he's adopted one that was supplied by equally generous-minded Mac users. The new one's quite nice!
Version as tested: 1.2.6.
Update 8/16/12.
You can't go wrong using the free, open-source Phoenix Slides software for browsing image folders and viewing slideshows. Nothing fancy, but it's very fast and has a few well chosen defaults. For example, its file browser is modeled on the Finder's columns mode, so it's quick and intuitive to find what you want. It can recursively display large numbers of images, either in icon view or full screen. In full screen mode, Phoenix Slides intelligently sizes the images for best viewing as on of its options. There are a lot of image browser/viewers out there, and Phoenix slides definitely warrants a look.